Peavey Classic 30 combo crackling and popping

[jappy]

Hi guys,

Just recently my Peavey Classic 30 combo has started crackling and popping after 5 - 10 minutes of playing. I have done a bit of testing and confirmed it is indeed the amp that is playing up.

Anyone have any idea what is wrong with it? My initial suspicion is a bad tube (not sure whether pre-amp or power), but I'd rather try and fix the problem first before spending money on an amp tech.

[jbltwin1]

Cracking-Popping-Peavey=bad solder joint. Nice amp though. You MIGHT have a resistor doing a crack up on you but the only way to find out is to do the chop stick test(NOT a pencil). Start tapping the components inside the chassis with the amp running after it's heated up. If you have ANY questions about being able to do this yourself, DON'T. The amp has 350 or so volts flying around in there and can get exciting(dangerous). It COULD be a bad tube but I vote for solder joint, then resistor, THEN tube. If that amp has a ribbon connector cable(don't remember), that's a place to clean and repair too.

[jappy]

Thanks for that reply. I'd rather not electrocute myself - many more years of guitar playing to come in this body!

Come to think about it, I did move the speaker connection cable around a bit and it got worse, but then the next time I played the amp it wasn't quite as bad anymore. Weird.

I've had this amp for nearly 2 years now without a problem. Is something like this likely to happen after say, a jolt in the back of a car?

[rockon1]

Originally Posted by jbltwin1

Cracking-Popping-Peavey=bad solder joint. Nice amp though. You MIGHT have a resistor doing a crack up on you but the only way to find out is to do the chop stick test(NOT a pencil). Start tapping the components inside the chassis with the amp running after it's heated up. If you have ANY questions about being able to do this yourself, DON'T. The amp has 350 or so volts flying around in there and can get exciting(dangerous). It COULD be a bad tube but I vote for solder joint, then resistor, THEN tube. If that amp has a ribbon connector cable(don't remember), that's a place to clean and repair too.

Not necessarily. Peaveys are also known for FX loop problems and besides it could be a tube.
Try putting a guitar cable from the send to the return of the FX loop-if your not using it when the problem happens. Sometimes the contacts in the jacks get dirty. If that doesnt do it try putting in your spare set of tubes. Could definately be a bad tube. If that doesnt do it then perhaps its a bad solder joint as previously mentioned or a bad ribbon? cable ...HTH-Bob

[VikingAmps]

Check the crimps on the speaker wires. I've had intermittent ones on those amps that drove me crazy thinking it was a bad solder connection that Peaveys are notorious for.

[Johnny Z]

Start with the tubes and check them one at a time against a new tube, you'll know if it's one of the tubes by simple elimination. Sometimes a tube socket can be the problem and arching due to a loose tube is a common problem with small amps if you play them loud tubes can loosen up over time, unless they have tube holders or shields. Cleaning a socket is easy, get some tuner cleaner from Radio Shack and spray it in the socket and work a small wire the size of the tube pin back and forth through each of the pin holes, get out any carbon. Then if necessary re-tighten the socket pin holes. Beyond that you may have some chassis issue a, bad solder joint or a defective part, but I think it's something simple. Classic 30's are well built little amps, the main problem I know of with them is vibration loosening things up, tighten every screw you can find on the amp and if you don't have tube holders on it get some for all the tubes. I'm glad your trying to learn about your amp. Take your time with it, it's a good way to learn something about your amp.

****One more thing be careful, be sure the amp is unplugged and the filter caps drained before working in yor amp.****

[rockon1]

Originally Posted by Johnny Z

Start with the tubes and check them one at a time against a new tube, you'll know if it's one of the tubes by simple elimination. Sometimes a tube socket can be the problem and arching due to a loose tube is a common problem with small amps if you play them loud tubes can loosen up over time, unless they have tube holders or shields. Cleaning a socket is easy, get some tuner cleaner from Radio Shack and spray it in the socket and work a small wire the size of the tube pin back and forth through each of the pin holes, get out any carbon. Then if necessary re-tighten the socket pin holes. Beyond that you may have some chassis issue a, bad solder joint or a defective part, but I think it's something simple. Classic 30's are well built little amps, the main problem I know of with them is vibration loosening things up, tighten every screw you can find on the amp and if you don't have tube holders on it get some for all the tubes. I'm glad your trying to learn about your amp. Take your time with it, it's a good way to learn something about your amp.

****One more thing be careful, be sure the amp is unplugged and the filter caps drained before working in yor amp.****

Or tube contact-good point.

[gnappi]

Originally Posted by jappy

Hi guys,

Just recently my Peavey Classic 30 combo has started crackling and popping after 5 - 10 minutes of playing. I have done a bit of testing and confirmed it is indeed the amp that is playing up.

Anyone have any idea what is wrong with it? My initial suspicion is a bad tube (not sure whether pre-amp or power), but I'd rather try and fix the problem first before spending money on an amp tech.

Peaveys are also infamous for intermittants on their insulation displacement connectors. After replacing the tubes that's a good place to start. If you can get the amp chassis on a bench and push on the wire connectors with a small wood dowel this may point out the problem. I usually remove one connector on one side of a wire in troublesome Peaveys and solder that side directly to the PCB. You cut in half the liklihood of problems in the future.

After that touching up solder is a good idea. Also, some Peaveys solder the tube socket directly to the PCB... BAD IDEA!!! On an amp that's moved a lot the PCB lands can crack leading to intermittant problems. Then you have a mechanical problem only a wire based solder bridge can fix.


Regards,

Gary

guitarsalon.biz